Disposable tray



Jan. 20, 1970 J. 1.. WENTZEL' DISPOSABLE TRAY 4 Sheets-Sheet 1 Filed June 14, 1968 INVENTOR WEW 7251.

ATTORNEY Jan. 20, 1970 J. L. WENTZEL 3,490,602

DISPO'SABLE TRAY Filed June 14, 1968 4 Sheets-Sheet 2 L5 5 30 33 %i 2 I 35 29 i 34 I 5 l 4 INVENTOR (JAMES L. Ws/vrza BY Saw KiTORNEY Jan. 20, 1970 w z 3,490,602

DISPOSABLE TRAY Filed June 14, 1968 4 Sheets-Sheet S a INVENTOR JAMES L. M/T/VTZEL BY Emma /ATTORNEY Jan. 20, 1970 J. L. WENTZEL 3,490,602

DI SPOSABLE TRAY Filed June 14, 1968 4 Sheets-Sheet 4 55 52 H V, 45 5g INVENTOR Y: L/AMES L. WEA/TZEL 44 9; j; v 40 i BY w WM WW ATTORNEY United States Patent 3,490,602 DISPOSABLE TRAY James L. Wentzel, Cottage Grove, Minn., assignor to Plastics, Inc., Ramsey County, Minn., a corporation of Delaware Filed June 14, 1968, Ser. No. 740,430 Int. Cl. A47f 3/14 US. Cl. 211-126 Claims ABSTRACT OF THE DISCLOSURE The disclosure illustrates a disposable tray including a frame made of thin walled plastic and a tray bottom panel made of paperboard. Means are provided on the frame for holding the panel in place. The panel is usually reinforced by cross-braces beneath the panel.

This invention relates to an improvement in disposable trays and deals particularly with a plastic serving tray which may be either partially or entirely disposable.

With the increase in size and rate of speed of airplanes, the problem of serving meals while aloft has greatly increased. Furthermore, the cost of operating high speed planes has made it necessary to cut down the weight of necessary items carried so that a greater pay load may be accommodated. For example, in many instances, thick walled glass tumblers have been replaced by very thin walled disposable tumblers, and relatively thick and heavy dishware has been replaced, by thinner walled plastic dishware. However, one of the heavier items used in the serving of meals on airplanes are the serving trays which support the various dishes, glasses, and the like used for the meal.

It has been found that the weight of the serving trays may be very materially decreased by providing a thin walled plastic framework supporting a panel of paperboard. The plastic framework may be shaped in such a manner as to provide the necessary strength, while still being very light in weight. The bottom panel of the tray may be made of paperboard which is also very light in weight. The plastic frames may be produced for a cost which is much less than the cost of the serving trays normally used. The paperboard sheets may also be produced at a fraction of the cost of the trays previously used. As a matter of fact, the trays may be considered disposable and discarded after use if it is so desired. On the other hand, if preferred, the frames of the trays may be retained for reuse, and the paperboard panels may be discarded.

As with any type of tray made with two separate parts, there is always a chance of leakage in the event liquid is spilled or tipped over unto the tray. For this reason, the plastic frame is preferably made of a series of U- shaped members capable of containing a considerable quantity of liquid. The structure is so arranged that if liquid should leak about the edge of the paperboard pan or panel, it will drain into the U-shaped members forming the plastic frame, and will not drain through the tray unto the table of another supporting surface.

A further feature of the present invention resides in the fact that the serving tray comprises a framework of thin walled plastic material, and the base of the tray comprises a sheet of paperboard or other material which is somewhat absorbtive, but which will tend to direct liquid about the edges of the tray and into the grooves forming the frame. Means are provided for holding the paperboard panel in position in the plastic frame until the paperboard is distorted sufliciently to disengage the same from the retaining means.

A further feature of the present invention resides in the 3,490,602 Patented Jan. 20, 1970 provision of a paperboard panel which is engageable into the plastic frame, and which is provided withmarginally extending flanges designed to border the flat panel. As a result, the portion of the plastic frame which would normally come into contact with food is covered, and the plastic frame may be reused without sterilization due to the fact that the frame itself has not come into contact with the food being consumed. The tray accordingly may be reused without being washed and sterilized, resulting in a very material cost to the airline or other organizations using the trays.

These and other objects and novel features of the pres ent invention will be more clearly and fully set forth in the following specification and claims.

In the drawings showing part of the specification.

'FIGURE 1 is a top plan of a composite tray, showing the general arrangement thereof.

FIGURE 2 is a bottom plan view of a portion of the tray illustrated in FIGURE 1 in somewhat enlarged form.

FIGURE 3 is a top plan view of the paperboard member used to form the bottom of the tray.

FIGURE 4 is a perspective detail of a corner of the tray, the view being partly in section and the position of the view being indicated in general by the line 44 of FIGURE 1.

FIGURE 5 is a sectional view through a portion of the frame, the position of the section being indicated by the line 55 of FIGURE 2.

FIGURE 6 is a view similar to FIGURE 5 but showing the paperboard tray member used in conjunction therewith.

FIGURE 7 is a perspective view of a slightly modified tray.

FIGURE 8 is a bottom plan view of the tray indicated in FIGURE 7.

FIGURE 9 is a perspective view of a corner of the tray frame illustrated in FIGURE 8.

FIGURE 10 is a vertical sectional view through a portion of the frame, the position of the section being indicated by the line 1010 of FIGURE 7.

FIGURE 11 is a perspective view of another modified form of tray construction.

FIGURE 12 is a model plan view of the tray illustrated in FIGURE 11.

FIGURE 13 is an enlarged sectional view of the tray illustrated in FIGURE 11, the position of the section being indicated by the line 1313 of FIGURE 11.

The serving tray A which is indicated in FIGURES 1 through 6 of the drawings includes two major separate parts, one comprising the plastic frame 10, and the other comprising the tray base 11. In the particular arrangement illustrated, the tray frame is made of plastic material, while the tray base is made of paperboard. While other material could similarly be used for the tray bottom, paper is at present preferred because of its low cost.

The tray A is rectangular in shape, and includes parallel side members 12 and 13 extending longitudinally of the tray, and end members 14 and 15 extending transversely of the frame at the ends thereof. The side members 12 and 13, as well as the end members 14 and 15 are of substantially the same cross-section.

The cross-sectional shape of the peripheral members 12, 13, 14, and 15 of the drawings is indicated in FIG- URES 5 and 6 of the drawings, and shown in perspective in FIGURE 4 thereof. The tray includes a bottom flange 16 upon which the paperboard tray bottom 11 may rest. The outer edge of the horizontal flange 16 is connected to an outwardly and upwardly inclined wall 17 which forms the outer peripheral wall of the tray. Along the inner edge of the horizontal flange 16, a channel-shaped structure is provided including a downwardly and inwardly inclined flange 18, a bottom flange 19 extending inwardly from the lower edge of the flange 17, and an upwardly and inwardly inclined flange 20 extending upwardly to the level of the bottom flange 16. As is clearly evident in FIGURES 5 and 6 of the drawings, this arrangement provides a peripheral channel which extends entirely about the frame, and which is capable of accommodating a considerable quantity of liquid. As the result, if liquid is spilled on the paperboard bottom panel of the tray, and drains downwardly through the corners thereof, it will drain into the channel extending just inwardly of the periphery of the tray, and the channel will prevent the liquid from draining completely out of the tray.

As indicated in FIGURES 1 and 2 of the drawings, supports are provided for the paperboard portion 11 of the tray to prevent the paper from sagging intermediate its edges. With reference to these figures, a longitudinally extending central strut 21 is provided parallel to the longitudinal edges 12 and 13 of the frame and midwa therebetween. A central transverse strut 22 is also provided extending parallel to the ends 14 and 15 of the tray frame and positioned intermediate therebetween. Struts 23 and 24 extend diagonally across between the corners of the frame to form an additional support and a means limiting the warping or twisting of the tray frame.

As is indicated in FIGURE 2 of the drawings, the longitudinal strut 21, the transverse strut 22, and the diagonal struts 23 and 24 are channel-shaped in cross-section, and communicate with the peripheral channels which have been described in such a manner that if liquid drains into any of the peripheral channels, it may also drain into the longitudinally extending strut, the transversely extending strut, and the diagonally extending struts 23 and 24. All of the struts are connected at the center of the tray by a central upwardly concave strut connecting member 25 as indicated.

Each of the frame members 12, 13, 14, and 15 are provided with means for retaining the paperboard tray bottom 11 in position. As indicated in FIGURES 4, 5, and 6 of the drawings, ears 26 forming a part of the peripheral walls 17 of the tray frame extend downwardly and inwardly from the side walls 17 to terminate well above the horizontal flanges 16. These lugs or ears 26 provide a means for retaining the paperboard tray bottom in position in its frame as will be described.

The paperboard tray bottom 11 is best indicated in FIGURE 3 of the drawings. The tray bottom comprises a rectangular panel which is hingedly connected along parallel fold line 29 to longitudinally extending side flanges 30, and which is connected along right angularly extending fold lines 31 to and flanges 32. The side flanges 30 include a pair of rectangular notches 33 which are spaced apart a distance equal to the spacing of the ears 26 connected to the longitudinal side wall members 17 of the tray frame. In a similar manner, the end Wall flanges 32 of the tray bottom 11 are notched as indicated at 34, the notches 34 being spaced apart a distance equal to the spacing of the ears 26 in the peripheral walls 17 of the ends 14 and 15 of the frame. Slits 35 extend from the base of each of the notches 33 and 34 to the adjoining fold line 29 or 31 to simplify the engagement of the flanges 30 and 32 with the ears 26 spaced about the periphery of the frame 10, and to permit independent flexing of the portions of the flanges 30 and 32 on either side of the slits 35.

As will be understood, the paperboard tray bottom portions 11 are normally flat and coplanar with the flanges 30 and 32. However, by pushing the paperboard panels downwardly into the frame 10, the marginal flanges 30 and 32 readily flex upwardly to lie in contact with the outwardly inclined walls 16 0f the frame. When forced downwardly sufficiently, the bases of the notches 33 and 32 clear the lower ends of the inclined ears 26 on the peripheral walls 17 of the frame, and the interengagement between the ears 26 and the walls of the paperboard tray bottom 11 lock the tray bottom into place within the frame and is retained therein. The

normal tendency of the paperboard tray bottom to return to its normal flat form urges the flanges 30 and 32 against the frame sides 17, and may hold the tray bottom 11 elevated as in FIGURE 4 until weight is placed upon the tray bottom 40. The modified form of tray illustrated in FIGURES 7 through 10 of the drawings is very similar to the structure described insofar as the tray frame is described. Accordingly, the same identifying numerals have been used. The main area of difference lies in the fact that the side walls 17 of the outer members of the frame are provided with inwardly extending ears 39, one of which is perhaps best illustrated in FIGURE 10 of the drawings. The paperboard tray bottom 40 is merely a rectangular sheet of paperboard which fits within the side walls 17 of the tray. The edges of the paperboard sheet 40 snap below the ears 39 and are retained in place by the ears. As will be seen, the tray B is very similar to the tray A with the main exception of the fact that the paperboard portion of the tray does not include marginal flanges extending along the upwardly inclined walls 17 of the tray, and the tray bottom retaining means are merely lugs or projections 39 which extend inwardly from the sides of the tray and engage over the edges of the sheet.

The structure shown in FIGURES 11, 12, and 13 of the drawings is virtually identical with that indicated in FIGURES 7 through 10 of the drawings with the exception of the shape of the tray. The tray C indicated in FIGURE 11 through 13 is circular in outline, and is provided with a cross-sectional structure best indicated in FIGURE 13 of the drawings. As indicated in this figure, the frame includes a bottom flange 44 having integrally secured to its outer edge an upwardly and out Wardly inclined wall 45. A trough-shaped portion underlies the marginal edge of the bottom portion of the tray and includes a downwardly extending generally cylindrical flange 46 extending downwardly and inwardly from the inner edge of the flange 46, a horizontally extending ring-shaped bottom flange 47 extending inwardly from the lower edge of the flange 46, and an upwardly generally cylindrical flange 49 extending up from the inner edge of the flange 47. The upper end of the flange 49 is coplanar with the upper surface of the horizontal flange 44, as will be seen in FIGURE 13.

A paperboard disc 50, preferably coated with a mois ture resistant coating such as cellulose acetate or other plastic material 51 rests upon the flange 44 and is held in place by a series of angularly spaced ears 53 beneath which the marginal edge of the disc 50 is pressed. Obviously, the disk 50 is made of material such as flexible paperboard which may be readily inserted or forced beneath the ears 53.

As is indicated in FIGURE 12 of the drawings, the tray bottom 50 is further supported by a pair of diametrically extending channels 54 which intersect at the center of the tray in a generally cup-shaped connecting area 56 at the point of intersection of the cross-members. The diametrically extending ribs 54 and 55 serve not only to assist in supporting the paperboard panel 50, but also act as a means of, communication between opposite sides of the tray frame. In other words, in the event liquid drains about the edge of the tray bottom 50 and into the channel-shaped circular drain member illustrated in FIGURE 13 of the drawings, the liquid may flow around the tray frame or transversely across the sides of the frame through the upwardly facing channels 54 and 55. Thus these channels serve not only as a support for the tray bottom, but also as a means of communicating the flow of fluid from one side of the tray to the other. A stiffening rib 57 may be provided near the top of the outer tray flange 45.

In accordance with the patent statutes, I have de scribed the principles of construction and operation of my improvement in disposable tray, and while I have endeavored to set forth the best embodiment thereof, I

desire to have it understood that changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A disposable serving tray including:

a peripheral rim of'thin walled plastic material,

said rim including a substantially horizontal tray panel supporting flange thereupon,

a panel of flexible material resting upon, and supported by, said supporting flange,

panel retaining ears supported by said rim above the level of said supporting flange and engageable over a panel supported by said flange.

2. The structure of claim 1 and in which said rim includes a peripheral wall extending upwardly and outwardly from said panel supporting flange. 1

3. The structure of claim 1 and in which said rim includes a continuous channel secured to the inner edge of said panel supporting flange.

4. The structure of claim 1 and including reinforcing members extending across said peripheral rim, having the upper surfaces thereof substantially coplanar with said tray panel supporting flange.

5. The structure of claim 1 and in which said peripheral rim is generally circular.

6. The structure of claim 1 and in which said peripheral rim is generally rectangular.

7. A tray including a peripheral frame member including;

a ring shaped horizontal flange on a common plane,

having inner and outer edges,

a upwardly and'outwardly extending flange secured to the outer edge of said horizontal flange,

a trough of generally U-shaped cross-section secured along its outer and upper edge to the inner edge of said horizontal flange,

a panel of flexible material resting upon, and supported by said horizontal flange, and

panel retaining ears secured to said upwardly and outwardly extending flanges and overlying said panel.

8. The structure of claim 7 and including marginal flanges on said panel adapted to extend upwardly and outwardly from the periphery of said panel to engage the upwardly and outwardly inclined flanges.

9. The structure of claim 7 and including reinforcing members extending between opposite sides of said trough beneath said panel.

10. The structure of claim 9 and in which said reinforcing members are channel-shaped in cross-section.

References Cited UNlTED STATES PATENTS 1,949,285 2/1934 Porter l0827 X 2,344,937 3/1944 Brazier 211l26X 2,986,438 5/1961 Smathers 10826 X 2,652,702 9/1953 Hintze 2l1l26 X 3,381,825 5/1968 Bessett 21l126 X NILE C. BYERS, 111., Primary Examiner US. Cl. X12. 108-42? 

